1. Field of the Invention
The present invention relates to a flame-assisted fuel cell (FFC) and, more particularly, to the integration of a FFC in a fuel fired furnace or boiler to enable the generation of both electricity and heat from the fuel's chemical energy, transforming the furnace/boiler into a Combined Heating and Power (CHP) system.
2. Description of the Related Art
Increased electricity consumption in the United States has been a growing problem that is only expected to increase in the future. A recent release from the United States Energy Information Administration forecasts growth in electricity consumption at an average annual rate of 0.9% between now and 2040. This projected growth will be made possible by a number of factors, the most significant of which is hydraulic fracturing techniques which have revitalized the United States natural gas industry. Combating this problem will require new solutions that improve the efficiency of the conversion from thermal energy to electrical energy.
One of the older solutions to this problem is to improve the efficiency of electricity generation by using the waste heat in a Combined Heat and Power (CHP) system. Such systems make use of the high quality waste heat to improve the overall efficiency of the system from the high 30's to the high 80's. The main challenge with these systems is transporting the heat across large distances to areas where it can be useful. Such issues have not been a challenge for large industries where the use of a large CHP system can be economical. However, the size and cost of such systems have made it difficult for the technology to impact the residential market.
Fuel cells provide a clean and versatile means to directly convert chemical energy to electricity. Among the many types of fuel cells, solid-oxide fuel cells (SOFCs) have received considerable attention owing to their simplicity (no moving parts), fuel flexibility and use of inexpensive catalytic materials. Unlike conventional CHP systems, which are complicated, noisy and dirty due to the use of internal conventional engines (moving parts), and have not been successfully scaled down to match the needs of a single family house or a small commercial building, SOFCs are all-solid electrochemical devices which can convert chemical energy to electricity directly in a highly efficient, silent and low-emission way. There is no liquid electrolyte with its attendant material corrosion and electrolyte management problems. The high operating temperature (500˜1000° C.) allows internal reforming, promotes rapid kinetics with nonprecious materials, and yields high quality by product heat for cogeneration. The total efficiency of cogeneration system can be reached ˜80%—far beyond the conventional power production system.
Conventional SOFCs are operated with a split cell, dual-chamber configuration: the anode chamber supplied with fuel and the cathode chamber with air. The dual-chamber SOFC (DC-SOFC) does not require catalytically selective electrodes, since the electrodes are exposed to separate gas streams, and is generally considered to be the technology of choice for large-scale stationary power generation. Although the conventional dual-chamber SOFCs (DC-SOFCs) show great potential as an electrical power generator, they are not widely applied due to high costs and difficulties in sealing. In addition, SOFCs are not considered suitable for applications that require frequent and rapid start-up and shut-down, as frequent heating and cooling cycles can cause internal stresses due to thermal expansion of the cell components and sealant. The single-chamber SOFC (SCSOFC) concept was proposed to address these issues, but the SC-SOFC is limited in fuel flexibility. Both DC-SOFCs and SC-SOFCs need external heating to maintain optimal operating temperatures since they rely on thermal catalysis. Furthermore, a fuel reformer or an evaporator is needed to avoid carbon coking in the fuel cell. These challenges have limited the application of SOFCs for compact and portable power generation.
Description of the Related Art Section Disclaimer: To the extent that specific publications are discussed above in this Description of the Related Art Section, these discussions should not be taken as an admission that the discussed publications are prior art for patent law purposes. For example, some or all of the discussed publications may not be sufficiently early in time, may not reflect subject matter developed early enough in time and/or may not be sufficiently enabling so as to amount to prior art for patent law purposes. To the extent that specific publications are discussed above in this Description of the Related Art Section (as well as throughout the application), they are all hereby incorporated by reference into this document in their respective entirety(ies).